Radiodynamic control of gyroscopes

ABSTRACT

18,408. Hammond, J. H. Aug. 14, 1913, [Convention date]. Gyroscopic apparatus. -In a method of controlling from a distance the steering of moving bodies, such as torpedoes, by means of electro-magnetic radiations, the moving body is provided with gyroscopic means to maintain a predetermined direction of movement, and means controlled bv radiant energy serve to correct any errors of the gyroscope. In the system described, the steering-mechanism of a vessel is normally controlled by a gyroscope, but when radiations are received the gyroscope is made inoperative by being locked to the vessel, which is then steered by radiant energy. The steering-mechanism is controlled by the piston 132 of a cylinder 131 connected by ports 151, 152 to passages around a channelled disk 142, which is normally locked to the hull 37 of the vessel and surrounds a shaft 25 kept fixed in direction in space by a gyroscope 112. As long as the vessel keeps the predetermined course, the pressure and exhaust ports 149, 150 in the rod 25 are closed by the ports 147, 148, but when the vessel deflects from its course fluid is admitted to one side or the other of the piston 132, thus adjusting the steering-mechanism. When the controlling- operator wishes to vary the course of the vessel, electro-magnetic radiations are transmitted and cause a solenoid 114 to admit pressure fluid to cylinders 157, 173. The cylinder 157 by attracting the pin 160 unlocks the disk 142 from the hull of the vessel, and the cylinder 173 locks the gyroscope to the hull by means of a pin 184 and forces a wedge-shaped member 182 through a slot 179 in the disk 142, thus preventing relative movement between the disk and the gyroscope and correcting any errors due to creep of the gyroscope.

l. H. HAMMOND, Jn.

RADIUDYNAMIG CONTROL 0F GYBOSCOPES. APPucATloN mso Aus.|4..v1-9|a. nsnewsu :uw f1. m1.

1. H. HAMMOND, JR.

RADIODYM/RPJHC` CONTROL 0F GYHOSCOPES. APPucAnom msu Ausw. 191s. www :uw n. 1911.

2 SHEETS-SHEET 2.

'HT STAT JOHN HAYS HAMMOND, JR., OF GLOUCESTER, MASSACHUSETTS,

RADIODYNAMIC CNTROL OF GYROSCOPES.

Mismo.

Specification of Letters Patent.

Patented June 6,1922.

Application filed August 14, 1913, Serial No. 784,691. Renewed July 11, 1917. Serial No.'180,021.

tion may be readily understood. I have disclosed a sing'le embodiment the'reof in the accompanying drawings. whereinl Fig. l is a view partially in transverse section and partially diagrammatic and in plan, of one form of apparatus for practicing my invention;

of the gyroscopic creep. and

Fig. 2 is a view. partially in vertical section and partially in elevation. of a portion of the apparatus shown in Fig. l.

In ,order to control moving bodies at a distance b'y radiant energy, such, for example. as vessels. it has. prior to the invention disclosed by me in my co-pending application Serial No. 777328` tiled July 14. 1913, been necessary that the operator shall at all times be in touch with and constantly exercising' control of the mechanism on board the vessel 'or other moving body which he is governing. In practice. and particularly in controlling the course of a torpedo or other movingr vessel by radiant energy. I have found that prior to the in- `vention disclosed in my said application.

there has been a constant need of sending signals in order to rectify the errors in the course of such vessels due-to wave. wind. current and other phenomena. In said application I disclosed a controller. preferably a gyroscope. which I employed to keep the vessel on a fixed. definite or predetermined course` except at such times as the operator desired to change the course.. and thereupon modified the action ofthe gyroscope upon the vessel. l thereby obviated the necessity of constant wave emission from the control I? ig. la is a diagrammatic representationl station for the purpose of compensating for deviations from a straight course due to the phenomena previously referred to or other causes. and thereby greatly minimized lthe possibility of the enemy .determining the wave lengths used in the control of the torpedo or other' vessel. and thereupon interfering with the control thereof.A In the present application. I have disclosed im-` proved means for varying or modifying the control of the vessel or other moving body by-'the controller. herein typified as a gyioscope.`and have disclosed one embodiment of means for compensating for any creep that may occur in the gyroscope.

Referring to the ,drawings wherein I have vshown a single embodiment of means' for carrylng out my invention and wherein I have typified" the. moving body as a vesself-preferably as torpedo boat. but which may be a land or air vehicle or appliance. s uch. for example. as an aeroplane, I have indicated the open receiving oscillatory circuit at l, this being connected to the winding 2 of a closed oscillatory circuit 3 having therein a stopping condenser 4, a condenser 5 and any suitable detector 6 for electrical,oscillations At 7 I have.represented a sensitive relay or other contact making device. These parts may be of any suitable construction. not herein necessary more fully to describe or to indicate. L

The controller preferably employed by me is a gyroscope, and I have diagrammatically represented the same at 8 in Fig. Q. The shaft or rod 9 of the gyroscope is normally maintained fixed in space thereby. and I employ suitable means operated vthrough the instrumentality of the receiving circuits l and El for modifying or vary- 'ing the action of the gyroscope upon the vesssel' and for effecting other objects relative to the gyroscopic control of the vessel. which will be hereinafter more fully Set forth. In' the 'disclosed embodiment of means for effecting these results. I have represented at l() and ll two soienoids which are adapted to be energized through the relay 7 controlling the circuit wherein said solenoids are positioned,

The plunger l2 of the solenoid l() is provided \vith a pawl or toothed formation lv adalited when the solenoid 10 is energized to in Figs engage circumferential teeth 14 upon a commutator, diagrammatically indicated at 15, and which is mounted for rotation upon a suitable shaft 16 having bearings in the hull of the vessel, Upon the commutator I provide a conducting band or ring 17 suitably insulated and which is connected by wires 18 and 19 with segments 2O and 21., The said segments are so positioned as alternately and respectively to make contact upon the rotation of the com'mutator` with brushes 22 and 23 which are respectively connected Yby wires 24. 25 to solenoids 26' and 27, and

which may be positioned in asecond relay circuit. Therefore, upon the receipt of a wave emission from the control station, the solenoid 10 is energized so as to energize either the solenoid 26 or the'solenoid 27, and through the operation of suitable instrumentalities to turn" the vessel to starboard or to port. At the same time. the solenoid 11 is energized to admit motive fluid from any suitable source of supply to the shaft or rod of the gyrosope 8. For this purpose. l have herein represented a cylinder 28 having therein a piston 29. the plunger 30 whereof is connected to the steering mechanism of the vessel and forms a portion of the rudder means. The opposite ends of the cylinder 2S with valve casings 31, 32 provided with admission ports 33. 34 communicating with any suitable reservoir or source of compressed air `or other motive fluid and' with exhaust ports 33, 34. said admission 'and exhaust ports being controlled by valves 36, which are formed with or operatively connected to the plungers 37, 38 of the solenoids 26. 27. Said valves are respectively provided withports 35, 35" and 36a, 361.

In the manner described or in any other suitable manner, the vessel is turned to stari board or to port upon the receipt of wave emissions from the control station. In order, however, to obviate the necessity of constant wave emission to keep the vessel uponI its course. l have provided a controller, herein typified as a gyroscope, and have provided suitable means whereby upon deection of the vessel from its true course compressed motive iiuid is. through the instrumentality of the said gyroscope, admittedto the cylinder 2S upon the proper side of the piston 29, so as to turn the vessel sufficiently to sta'rboard or to port to return it to its true course.

The hull of the vessel :is indicated at B9 1 and 2. Upon the hull but indethereof, and also of the gyroscope shaft 9` I ,have mounted a ported member herein represented as a disk 4() of any suitable size. The said disk is provided with ports or passages 41. 42. 43 and 44 leading from the center thereof to the periphery. and preferably enlarged at their inner ends, as indicated in Fig. 1, so as to provide relapendent rod or fication of the course of the vessel.

tively narrow separating walls 45 and 46. The rod or shaft 9 of the gyroscopel 1s provided with an intake pipe'47, by which mo- Herein for the purpose I have represented the cylinder asl provided at its opposite ends with ports 49, 50. rlhe port 49 is in communication by passages 5l with the port 44 of the disk 40 and by passage 52 with the port 41 of said disk. The port 50 of the cylinder 2S is in communicationv by passage 5B with the port 43 of the disk-10 and by passage 54 with the port 42 thereof, so thatupon rotation of the disk 40 in either direction by movement of the vessel, the intake and eX- haust passages 47, 48 in the shaft or rod of the gyroscope will be placed in communication with .the passages 41 and 43 or with the passages 42 and 44, so as to ladmit motive fluid to one end or the other of the said cylinder 28 and to permit the motive uid to be exhausted from the opposite end of. said cylinder, thus moving the piston 29 to the right orto the left as the case may be and defiecting the vessel toward starboard or toward Normally the disk 40 is locked to the hull of the vessel by suitable means, so that as the vessel deviates to the right or to the left the disk 40 is correspondingly' turned to bring the ports thereof into register with the intake and exhaust passages in the gyroscope rod, and thereupon'to effect the recti- So long as thevessel maintains its true course, the walls 45, 46 of the disk 4() are opposite the intake and exhaust passages 47, 48 of the gyroscope rod 9, and it will be observed that the said walls are relatively thin, so that very slight or minimum movement ofthe vessel to starboard or to port will result in such displacement of the walls 45, 46 as to open the passages 47 and 48 to the proper ports 41, 42, 43, 44 of the disk 40.

lVhile l may employ any suitable means for locking the disk 4() to the hull, I have in Fig. 2 represented a cylinder 55 having therein a piston 5G normally pressed upward by the coiled spring 57 and provided with a plunger 58 passing through a hole or perforation 59 in the portion 60 of the hull and into a socket (31 in the under face of the disk 40. Above the piston the cylinder is provided with a port 62 which is connected by passages G3. 64 to some suitable source of motive i'iuid supply, and prefer- `operatively connected to lthe plunger 68 of the solenoid 1l, so that upon energization of the latter the valve 66 is moved against the stress ofthe coiled spring 69, solas to bring the admission port 67 of said valve into register with the passage 64 and thus toplace said passage in open communication with saidsource of fluid supply, thus admitting said motive fluid into the cylinder 55 above the piston 56 thereof, forcing said piston downwardly against the stress of the spring 57 and withdrawing the plunger 58 of said piston from the socket 6l of the disk 40. In this manner, the said disk is re.-

f leased from the hull,so that it is no longer turned by deviating movements ofthe latter.

fI- contemplate connecting the gyroscope to the hullofthe vessel or other moving body u'pon release of the disk 40-from the hull, and preferably the releaseof the said disk from the hull andthe engagementof the'gyroscope and the hull are effected simultaneously. Therefore, I terminate .the functioning` ofthe gyroscope b connecting .itl tothe hull, at the time thatt e control of the gyroscope upon the vessel is terminated.

' Thereupon the vessel may be' lcontrolled from the distant sending-station, and when,

the functioning of the gyroscope is to -be resumed, the gyroscope 1s released from thev hull and the disk 40 is again locked tothe hull. 1While these results may be secured in any suitable manner, `I have disclosed the preferred "embodiment of means for effecting the result. v

Suitablyv attached to the gyroscope rod 9 is a cylinder 70 having therein a'piston 71 provided With a plunger 72 extending through the lowerlhead of'said cylinder. Surrounding said plunger Within the cylinder is a coiled spring'73 which normally holds said piston elevated. Above the .said piston, the cylinder 70 is provided with a port 74 which is in communication by a passage 7 5 with the passage 64 so that when the admission port 67in valve 66 is movedv into register with the said passage 64 upon energization of the solenoid 11, the compressed motive fluid is admitted not only into the cylinder 55, so as to force the piston 56 thereof'downvvardly, but also into the cylinder so as to force the piston 72 thereof downwardly against the tension of its spring 73.

l I have provided suitable means herein associated with the cylinder 7 0 and operated through its connection with the compressed motive fluid supply, positively to maintain of motive fluid to and from the cylinder 2.8

through the instrumentality of the gyroscope at such times. When the disk 40 is disconnected from'the hull and the vessel is therefore no longer under the control of the gyroscope, motive'fiuidfis admitted to the cylinder 28 only through the ports 33 and 34, so that the vessel is turned to starboard or to port by reason of the wave impulses transmitted from the distant control station.

In order thus to holdthe disk 40 in fixed relation to the gyroscope, and therefore to prevent the admission of motive fluid to or its exhaust from the cylinderthrough the passa-ges 47, 48 of the gyroscope, I have herein represented the saidk disk as provided with va-l'edge or projection 83 of the hull 39.

lVhen the piston 71 `is forced downwardly, thewedge 79 enters thel slot 76 and the downwardly eXtendinor end 8l enters the hole in the hull, there-by locking the gyroscope to the hull and also holding the disk 4() in such position that its walls 45 and 46 close the intake yand exhaust passages 47, 48 of the gyroscope rod. In this position ofthe parts,` the. gyroscope no longer controlsthe vessel since its gyroscopic function has been neutralized or temporarily terminated b-y reason of thefact that it is locked to the hull. At such time, therefore, the gyroscope, which I have herein represented as provided with a disk 84 rotating upon ball bearings `85, will rot-ate out of its normal azimuth. uInasmuch, therefore as the gyroscope is locked to the hull and no longer controls the vessel, the latter is subjected to the control of the operator at the distant station, and upon the receipt of wave impulses by the receiving circuits l and 3, the vemel is turned to starboard or to port, as the. case may be;

I have discovered that therel is a tendency of the gyroscope during the time it is functioning to creepl in one direction or the other. That is to say., there is a slight oscillation of the gyroscope from its true azimuth-north and south-due mainly to the slight mistakes in the original sett-ing. This causes a complete' oscillation of thegyro-scope be reduced to one degreel or less, and the longer the gyroscope is run, the less becomes the oscillation. In F ig. la, I have graphically indicated by curve the oscillation or creep of the gyroscope. This results in slight rotative movementI of the rod 9 relative to the disk 40, thereby opening the intake and exhaust passages 47 48 thereoi:` at times when no rectification of the course of t-he vessel is required. jection and compensate for the creep of the gyroscope which has occurred during its functioning, by causing the wedge7 9 to enter the slot 76 of the disk 40, thus turning the said disk in a clockwise or contraclockwise direction so as to bring its walls 45, 46 in register' with and to close the intake passage 47 and the exhaust passage 48 of the gyroscope rod, and therefore to maintain them closed during the periods that. the gyroscope is locked to the hull. The creep of the gyroscope has thus been compensated for and corrected at the time the functioning of the gyroscope is temporarily terminated and theI vessel is subjected to the control of the operator at the distant sending stat-ion.

At such times, therefore, as the operator at the distant control station is sending wave impulses, the gyroscope is locked to the hull, and the disk 40 is held in such relation to the passages 47, 48 of the gyroscope rod that motive fluid c annot be admitted through the instrumentality of the gyroscope to the cylinder 28. Therefore the piston 29 'of said cylinder 28 is moved toward the right or to- Ward the left solely through the admission ot motive fluid through the intake passages 33, 34.

Upon the termination of the wave impulses, the energization of the solenoids 1l, 26, 27 ceases, whereupon the valve 66 through the instrumentality of the spring 69 closes the passage G4 to the admission port 67 and places it in register with the exhaust extension 67 thereof. Thereupon the motive fluid is exhausted through the pipes G3, 75'

from the upper ends of the cylinders 55, 70, and the spring 57 projects the plunger 58 into the engagement of the. socket l with the disk 40, thereby again loc-king the disk to the hull, and the spring 73 lifts, the piston 7l so as to withdraw the Wedge 79 from the slot 76 and to withdraw the projection 8l from the hole or socket 82 of the hull. The gyroscope is thus unlocked or released from the hull, and it is permitted to resume its normal function and to maintain thev vessel upon its predetern'iined or fixed course.

Vhen the disk 4() is locked to the hull` it turns with the hull' and thus the fluid under pressure is admitted through the passages in said disk 40 as it and the vessel turn about the rod 9 oi thegyroscope, which remains fixed in place. The gyroscope now functions in its accustomed or proper manner. lVhen, however, the plunger 5S is re- I overcome this olo.

leased from the disk 40, then the gyroscope is clutched to the hull at 8l, 82, 83, and cannotJ then function as a gyroscope. The gyroscope is then turned by and with the hulll and. no longer controls the admission of fluid under pressure into the cylinder 28. At such time,that is, when the gyroscope is clutched to the hull,-th`e gyroscope is clutched to the disk by the plunger 79. This, however, is 'for the purpose o f turning the disk 40 With'the rod 9 of the gyroscope in order to prevent fluid under pressure being admitted thro-ugh tube 9 into the cylinder 28. This is done because. at this time fluid under pressure is admitted to cylinder 28 not by the gyroscope, but by radiant energy through the action of solenoids 26, 27.

Thus the plunger 58 clutches the disk 40 to the hull, but'the wedge 79 clutches the gyroscope to the disk 40, and this latter is done at the time when the. gyroscope is not functioning as a gyroscope, butvis clutched to the hull. l

I do not by the construction herein disclosed compensate for the creep of' the gyroscope by returning the. gyroscope to its absolutely proper position, but I correspondingly t-urnv the disk 40 by an amount equal to the error of the gyroscope. T he fault occurring through creep of the gyroscope is that it would or might eventually move the intake and exhaust passages 47, 48 of the gyroscope rod 9 out of register with the Walls 45, 46 at a time when this is not required to keep the vessel on its course. This difficulty. or danger is overcome or prevented by correspondingly moving the disk 4l) through the action of the wedge 79. It will be observed, viewing Fig. l, that it is import-ant to preserve the normal closed relation of the intake and exhaust passages 47, 48 of the gyroscope rod 9 With the walls 45, 46 of the disk 40. To do this, it is not necessary to restore the gyroscope to its true position. It may and preferably is done byv turning the. disk 40 to compensate for the described error in the movement ot' the. gyroscope. Such error, owing to creep of the gyroscope. is generally small, and the socket (S1 is large enough in diameter to receive the point ot the plun-A ger 58 in the. compensated position ot' the disk 40, or it' desired the disk 4() may be provided with a plurality ot sockets, as disclosed in my co-pending application Serial No. 778,828.

Having thus described one illustrative embodiment of my invention. l desire it to he understood that although specific terms are employed. they are used in a generic. and descriptive sense and not for purposes of limitation. the scope oi the invention being'set. forth in the. following claims.

Claims:

1. A system for controlling the operation of moving bodies at a distance by radiant energy including in combination, a vessel to be propelled having a gyroscope to impart thereto a predetermined or definite direction of movement, a ported member having movement relative to the vessel and the gyroscope, means to lock said member to said vessel, means responsive to radiant energy from a distance to unlock said member and vessel, and co-acting means to compensate for creep of the gyroscope.

2. A system for controlling the operation of movingbodies at a distance by radiant energy including in Combination, a vessel to be propelled having a gyroscope to impart thereto a predetermined or definite direction of movement, and provided with in-take and exhaust passages, a ported member having movement relative to the vessel and said gyroscope, means'to lock said member and vessel together, means responsive to radiant energy from a distance to unlock said member and vessel, and means responsive to radiant energy from a distance to maintain the ports of said member out of alignment with the in-take and exhaust passages of the gyroscope when said member is unlocked from the hull.

3. A system for controlling the operation of moving bodies at a distance by radiant energy including in combination, a vessel to be propelled having a gyroscope. to impart thereto a predetermined or definite direction of' movement and having intake and exhaust passages for motive fluid, a ported member adjacent to said gyroscope and having movement` relative thereto and to the vessel, and means responsive to radiant energy from a distance to prevent registerv .of said passages and ports due to creep of the gyroscope.

4. A system for controlling the operation of moving bodies at a distance by radiant energy 'including in combination,a vessel to be propelled having a gyroscope to impart thereto a predetermined or definite direction of movement and having intake and eX- haust passages, a member adjacent said gyroscope and having movement relative thereto and to said vessel, means to lock said vessel and member together. and means responsive to radiant energy Jfrom a distance to unlock said vessel andv member and to lock together the vessel and gyroscope.

5. A system for controlling the operation of moving bodies at a distance by radiant energy including in' combination, a vessel to be propelled having a gyroscope to impart thereto a predetermined or definite direction of' movement and having intake and exhaust passages, a member adjacent said gyroscope and having movement relative thereto and to said vessel, means to lock said vessel and member together, and means responsive to radiant energy from a dist-ance to unlock said vessel and member and to lock together the vessel and gyroscope and to compensate for creep of the gyroscope tralize the action of'said gyroscope, andj;

means to prevent communication between said passages and ports during the period of' neutralization of said gyroscope.

7. A system for controlling the operation of moving bodies at a distance by radiant energy including in combination, a vessel to be propelled having a gyroscope to impart thereto a predetermined or definite direction of movement, a gyroscope rod having intake and exhaust passages for motive fluid, a ported member surrounding said rod and having movement relative thereto, said ports being positioned to effect communication between the same and said passages upon slight movement of said member.

8. -A system for controlling the operation of moving bodies at a distance by radiant energy including in combination, a vessel tobe propelled having a gyroscope to impart thereto a predetermined or definite direction of movement, a gyroscope rod hav ing intake and exhaust passages for motive fluid, a ported member surrounding said rod and having movement relative thereto, said )orts bein(lr arranged in )airs to communi-J. D P

cate respectively with said intake and exhaust passages, the ports of each pair of' ports being narrowly spaced, to effect communication with said passages upon slight.A

movement of said member.

9. A system for controlling the operation of moving bodies at a distance by radiantenergy including in combination, a vessel to be propelled having a gyroscope to impart thereto a predetermined or definite direction of movement, motive fluid supply means controlled by said gyroscope, means responsiveto radiant energy from a distance to neutralize the action of said gyroscope, and c-o-acting means to prevent functioning of said motive fluid supply means during the period of neutralization of said gyroscope.

l0. A system for controlling the operation of moving bodies at a distance by radiant energy including in combination, a vessel to be propelled having a gyroscope to impart thereto a predetermined or definite direction of movement, motive fluid supply means controlled by said gyroscope, means responsive to radiant energy from a distance to neutralize the action of said gyroscope,

iio

and eo-acting means also responsive to radiant energy from a` distance to prevent Jtunctioning ot' said motive fluid supply means during the period of neutralization oi said `iivroscope.

ll. system tor controlling the operation ot' moving bodies at a distance by radiant energy including in combination. a vessel to be propelled havingl a gyroscope to impart thereto a predetermined or definite direction ot movement and having intake and exhaust passages. a member adjacent said gyroscope and having movement relative thereto and to said vessel. means to lock said vessel and member. and means responsive to radiant energy from a distance to disengagevsaid vessel and member and to engage said vessel and gyroscope.

l2. A system tor controlling the operation ot moving' bodies at a distance by radiant energy including in combination, a movable body having a gyroscope to impart thereto a predetermined or definite direction of movement. motive fluid supply means controlled by said gyroscope. means responsive to radiant energy from a distance to neutralize the action ot' said gyroscope, and co-aeting means to prevent functioning ot said motive fluid supply means during the period of neutralization of said gyroscope.

13. A system for controlling the operation of moving bodies at a distance7 including in combination, a body to be propelled provided with means to maintain 'a predetermined or definite direction of bodily movement. and means controlled from a distance and carried b v and movable with respect to said direction maintaining means to compensate for errors in the latter.

l-l-. system for controlling' the operation of moving bodies at a distance including in combination. a body to be propelled provided with a controller to maintain a predetermined or definite direction ot bodily movement. rudder means acted upon by said controller, thereby to maintain said predetermined direction ot bodily movement. and means carried by said controller and movable with respect thereto in response to radiant energy to compensate t'or errors ot said controller. and thereby to prevent. movement ot' said rudder means through the controller due to errors oi' said controller.

l5. A system for controlling the operation ot' moving bodies at a distance by radiant energy including in combination. a body to be propelled provided with a controller to maintain a predetermined or definite direction ol bodily movement thereof. rudder means governed by said controller. and means carried by said controller and movable with respect thereto to preventI errors of saidicontroller from etliecting said rudder lillli.

16. A system for controlling a dirigible body. including in combination a body provided with means tor maintaining said body upon a pre(letermined course. said means including two elements separately rotatable about`a common axis with respect to said body.,`one otl said elements being normally held against rotation in spaceawith respect to said axis. and the. other ot' said elements being normally held against rotation about said axis with respect "to said body.

1T. system Yfor controlling a dirgible body. including in combination a body provided with means tor maintainingr said body upon a predetermined course. said means including two elements separately rotatable about a common Yaxis with respect to said body. one ot' said elements being normally held against rotation in space with respect to said axis, and the other ot' said elements being normally held against rotation about said axis with respect to said body and means controlled by radiant energy for modifying' the functioning of said first named element.

1S. A system tor controlling a dirigible body, including in combination a body provided with means tor maintaining said body upon a predetermined course, said means including two elements separately rotatable about a common axis with respect to said body. one ot' said elements being normally held against rotation in space with respect to said axis, and the other ot' said elements being normally held against rotation about said axis with respect to said body and means controlled by radiant energy for moving said second named elementiabout said axis with respect to said body.

19. A system tor ccmtrolling a dirigible body. including in combination a body provided with means for maintaining said body upon a' predetermined course, said means including two elements separately rotatable about a common axis with respect to said body, one ot said elements beingnormally held against rotation in space with respect to said axis. and the other ot said elements being normally held against rotation about said axis with respect to said body and means-responsive to radiant energy Jfor modifying the action ot said iirst named element. and means responsive to radiant energy for rotating said second named element aboutv said axis with respect to said body.

Q0. A system for controlling a dirigible body. including in combination a body provided with means for maintaining said body upon a predetermined course, said means including two elements separately rotatable about a common axis with respect to said body. one ot said elements being normally held against rotation in space with respect to said axis. and the other of sai-'l elements being normally held against rotation about said axis with respect to said` body and means responsive to radlant'en- 'e1-5y for holding said lirst named element against rotation and rotating another of said elements about said axis.

23. rl`he combination with a plurality of elements separately rotatable upon a conimon axis` and means responsive to radiant energy for holding one ot said elements lagainst rotation and simultaneously rotating another ot' said elements about said axis.

In testimony whereoty I have signed my name to this speeifieation, in the presence of two subscribing witnessesY Vitnesses:

Frrz J. BABSEN, JOHN CUNNINGHAM. 

